Cylinder relief valve



Aug. 4, 1925. 1,548,098 w. RAYMOND CYLINDER RELIEF VALVE Filed Jan. 2, 1925 mm/Tan I l TTURNEY paa'a' a not easilyjput'out of order.-

body portion of a second valve acting as a Patented Aug. 4, 1925.

"PAT NT, O'FFlCE. -g

wean RAYMo Djor-EAsToN, PENNSYLVANIA, ASSIGNOR TO PENNSY VANIA PUMP & COMPRESSOR corrrANY, or ASYLVANI,A.

EASTON,PEN1\TSYLVANIA, A'GOBPOB'ATION or BENN- CYLINDER RELIEF VALVE.

' Application fi1e'dianuary 2,1 925. semi No. 53.

To all whom it may concern:

Be it known that I, 'WARD RAYMOND, acitizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Cylinder Relief Valves, ofwhich the followingis a specification.

This invention relates to relief valves and" 1n particular to a relief valve hav ng 'auto--' Ina-tic means for openingltfand being of'an improved and novel form,

Itis an object of the present invention to" formpof relief "valve "to said poppet 'pr ovidejan' improved having "a mlmmum clearance spacey;

and

when open a nude valve opening for "the-Q fluid being ejected from 'th'e compressor cylinder.

' It is another 'ot e'aj of' the invention a; provide a poppet forinof relief'valve adapt ed to 'be actuated .by v a piston noved by'suit-e able regulatingmeans and having its stein passing centrallythrongli and" guided by the check valvefi Another object ofthe invention is to pro J being movable longitudinally within amm er: I

"With theabove' and other objectsin view,

. my invention cons sts in the features of con- 7 .iting the scope of the invention,

Y .stru'ctionand operation set fortli in the following specification and-illustrated in the accompanying drawing. 7 I

In the accompanying drawing annexed hereto and forming a part of this specification, I have 'shown my. invention embodied ina relief valve'for an air compressor, but it will be understoodthat the invention can be otherwise bodied and that the drawing is not to be construedas defining or liin- I v I I .the claims appended to this. specificationf being relief upon for that purpose;

'I 't edr n c r a s (Figure 1 'sa longitudinal'sectional view ofj-th'e'scomplete valve 'Inadein accordance I with'the p-resent' 'finvention, and

' the invention.

' pet valve.

end of the valve stem Fig. 2 is a plan view of the same. I In the abovedrawing, I have shown'bu one form of the inventionwhich is now deemed preferable, but it is to: be understood that changes and modifications may be'made within the scope of the appended claims Without departing fromthe-spirit of I Briefly, and in its broadest aspect, my invention comprises the following principal operative parts? first,- a body member; secend, a poppet; valve 7 therein extending centrally through the body member'; third,a check valve openingoppositely able within thelbody memberand having its movements controlled by fluid pressure sup plied by a regulator or unloaderymovement having a stem valve {fourth .a pi'ston movof this piston opening and closing the pop--v 7 Referring more in detail to the figures of; the drawing, I having a connection jtached to a"cornp'ressor cylinder.

provide afbody member '10 operates. A valve'seat '15 isformed in'the wall ofthe body member-10 against which seat 15 to retain it in ll adapting it to beat- This con- "nection 1.1 isfadjacent an opening 12 to a" valve chamber '13 in which a poppet'valve 14 closed position,]aspring 16 1s provided act- 7 ing againstopening12 and provides a suitable space for the spring 16."

The when: is provided with an elongat ed-stem 18 extending centrally and downj ward through the body; member 10, its'lower I end resting in a socket 27in a piston 19. In

through a. central hole guided accurately to its seat; as the lower socket 27 and'the upper end is: guided in the By means of an opening 22 providedcentrally in a plug-23 'closin'gthelower end of the body member 10 air under pressure may' theupper side of the valve 14L. A recessed cap 17 threaded into sth'e upper end of the body member 10 encloses the valve 18 isheld central in admitted to the space 'belowthepiston19 I froma'suit'aible regulator or unloa'der.

J In

regulating devices of this general type, close fitting pistons and other moving parts are objectionable, as, if they are madeclose fitting enough to hold the air under pressure without material leakage, they are liable to get out of order and stick by failure of proper lubrication, warping out of shape, or by the entrance of particles of grit or dirt carried in by the air. To avoid this objection the piston 19 may be made to fit loosely within the body 10 and, at the top of the space within which the piston 19 operates, a bevelled valve seat 28 is formed. This valve seat 28 co-acts with a correspondingly bevelled valve surface 29 formed on the upper end of the piston 19. These two surfaces 28 and 29 may be ground to a pressure tight joint so that when the piston 19 is moved to its upper position by air through the opening 22 the leakage is but momentary during the movementupward of the piston 19. As soon as the piston 19 reaches its upper position no further leakage occurs, as the piston valve surface 29 is in contact with the valve seat 28. With air pressure admitted to this space thepiston 19, which is preferably of much larger area than the valve 14, is elevated, thus forcing upward the stem 18 and lifting the valve 14 from its seat 15. By reason of the enlarged area of the piston 19 acted on by the discharge, pressure of the compressor is enabled to open the valve 14 against the pressure of spring 16 and against the pressure in the space 12, forcing the valve 14 toward its seat. The advantage of piston 19 being materially larger in area than valve 14 is that as equal pressures per unit area act upon both the valve 14 and the piston 19, the larger area of the piston 19 creates a greater total pressure on this piston and causes it to move upward promptly upon the admission of discharge pressure through the opening 22. Were the piston 19 of a diameter equal to that of the valve 14 the piston 19 would be raised only when the pressure above valve 14 is less than thedischarge pressure, as during the suction stroke of the compressor. With the construction as shown, the piston 19 may be raised to unload the compressor at any point in the compress. ing stroke of the compressor. With valve 14 in its open position, fluid is permitted to pass from the compressor cylinder to which the body member 10 may be attached through theopening 12, the valve chamber 13, and finally through an opening to atmosphere 24. In passing through the chamber 13 the air opens the check valve 21 against the pressure of a light spring 25. Between each passage of air the check valve is closed tightly and quickly by the spring 25. so that no air or other fluid is permitted to pass in a retrograde manner past the check valve 14.

through the opening 12 and into the cylin: der of the compressor. To prevent pressure building up in the hollow portions of the check valve 21 and piston 19 within the body member 10, holes '26 are provided in the check valve 21. These at all times permit y eakag of a i o t e in erio of the y m r 10 pa s ng ou through the opening 24 into atmosphere.

As soon as the pressure is released below the piston 19, this piston is forced downward by spring 25, and simultaneously with this movement of the piston 19 the valve 14 is forced down against its seat 15by the spring 16. As soon as valve 14 is again closed, nor mal operation of the compressor is resumed. It will be noted also that the check valve 21 may be loosely fitted in body 10, as the body portion of this valve acts only as a guide.

Throughout this construction therefore all moving parts are loosely fitted and the valves are of the annular or poppet type so that they may be quickly ground to pressure tight joints. This construction facilitates the manufacture of the component parts as they may be completely finished except upon their seats by automatic or production machines.

Also when the valves become leaky they may be readily re-ground and do not require re,- placement of parts. i

It will be understood that a relief valve will be prov de at c en of a compressor cylinder, if double acting; and that, if de si ed, vari usm difi at o s may be mad i the details of construction. With the valves 14 and 21 and the piston 19 arranged longidina y a c ntrally, the body membe 10 is readily formed with the requisite cylinr l. ace nec ss y for hese parts, and i hin hi h hey oper te.

I claim:

1. A relief valve for compressors comprismg in combination, a body member, a valve therein normally maintained closed, a valve stem on said valve extending longitudinally ithin h body mber, a heck v lve adapted toopen in the opposi e directio from said first valve, independent means maintaining said valves 0105661, and pressure u t me s t op n: s id first valve.

2. A relief valve for compressors comprising in combination, a body member, a valve therein means normally maintaining said valve closed, a valve stem on said valve tending longi u inal y ithin the body member, a check valve OPPQ iteIy disposed to said first valve and forming a guide for said valve st m, moan normally ho ding said c k val clo d, and] pressu e a tod m ns o open said. first va e.

3. A elief v e for compressor ompris i g'i c m in tion, a body membena alve therein normally maintained 61 5 .56, a valve stem on said valve extending longitudinally it in th b dy membe a c ec alve i l gn n w th a d fi st valve and oppos d.

the et said val e stem P ssing centrally through said check valve whereby it is guided by said check valve, a spring normally forcing said check valve to its closed position, and a piston engaging said valve stem whereby movement of said piston is adapted to open and close said first valve.

4. A relief valve for compressors comprising in combination, a body member, a valve therein normally maintained closed, a valve stem on said valve extending longitudinally within the body member, a check valve in alignment with said first valve and opposed thereto, a spring normally forcing said check valve to its closed position, said valve stem passing centrallythrough said check valve, and a piston aligned with the above said valves engaging said valve stem whereby movement of said piston is adapted to open and close said first valve.

5. A relief valve for compressors comprising in combination, a body member, a valve therein normally maintained closed, a valve stem on said valve extending longitudinally within the body member, a check valve in alignment with said first valve and opposed thereto, said valve stem passing centrally through said check valve whereby it is guided by said check valve,- a spring normally forcing said check valve toward its closed position, a piston of larger area than said first valve and in alignment therewith, the lower end of the valve stem being engaged by said piston whereby movement of said piston will open and close said first valve, and means to admit fluid under pressure to actuate said piston.

6. A relief valve for compressors comprising in combination, a body member, a valve therein normally maintained closed, a piston within said body member, means to admit fluid under pressure to raise said piston to open said valve, a check valve in said body member adapted to open in a direction opposite to said first valve, a valve seat in said body member, and a valve surface on said piston adapted to contact with said valve seat in said body member when in its raised position.

7 A relief valve for compressors comprising in combination, a body member, a valve therein normally maintained closed and having a valve stem extending through said body member, a piston within said body member, means to admit fluid under pressure to raise said piston to open said valve, a check slidable on said valve stem, a valve seat in said body member, and an annular valve surface formed at the upper end of the piston and adapted to contact with said valve seat when the piston is in its raised position.

In testimony whereof, I hereto aflix my signature.

WARD RAYMOND. 

